Bridge construction.



PATENTED JUNE 16, 1908.

v. S. HEWETT. BRIDGE CONSTRUCTION.

APPLICATION FILED MAR. 4, 1907. RENEWBD 001221. 1907.

2 SHEETS-SHEET l.

PATBNTBD JUNE 16, 1908.

S. HEWETT. 4 BRIDGE CONSTRUCTION.

LPPLIOATION FILED 11,111.4, 1907. nmmwnn 00T. 21. 1901.

2 SHEETS-SHEET 2.

OFFICE.

WILLIAM S. HEWETT, OF MINNEAPOLIS, MINNESOTA.

BRID GE CONSTRUCTION.

Specification of Letters Patent.

Patented .rime 16, 190s.

Application filed March 4, 1907, Serial No. y360,592. Renewed. October 21, 1907. Serial No. 398,509.

To all whom it may concern:

Be it known that I, WILLIAM S. HEWETT, of Minneapolis, sota, have inventedv certain new and useful Improvements in Bridge Construction, of which the following is a specification.

A The object of my invention is to provide a bridge of`simple, economical construction and one that can be easily and quickly erected without the employment of skilled labor.

A further object is to provide a' bridge that will be strong and durable and one that by reason of its ease of erection is particularly adapted for single span bridgeson country highways. y

A further object is to provide a beam having an elongated comparatively narrow tread surface adapted when a series of the beams are placedto'gether with contacting edges, to form a continuous floor or roadway.

My invention consists, generally, in a bridge composed of a series of reinforced concrete beams running lengthwise of the rods passing transversely through the beams composing the bridge and tying or binding them .securely together.

Further, the invention consists in various constructions and combinations, all as here? inaftcr described out in the claims.

In the accompanying drawings, forming part of this s iecilication, Figure l is asectional View illustrating a single span bridge embodying my invention, substantially on the section line y-dj of Fig. 2. Fig. 2 is a transverse sectional view on the line -ac of Fig. l. Fig. 3 is a similar View on the line 2&2 of Fig. 1.. Fig. 4 is andetail sectional view on the line ww) of Fig. 2. Fig. 5 is a top view of one "of the concrete beams of. which the bridge is composed. Fig. 6 is a bottom View of the same.

lIn the. drawings, 2 represents the bridge abutmcnts having suitable seats 3 formed therein, ande are the beams which, when glacedside by side, form the roadway of the ridge. The beams are made of suitable length and Width, but for convenience in handling them, I prefer to mold them two feet in width, though the length and width may bc varied according to the size of the bridge to be built and the facilities for handling the beams. I do not wish to be confined to any particulardimensions.

and particularly pointed Hennepin county, Minnebridge, and Y The ends of the beams will have flattened under surfaces 5 to rest uponv the seats of the abutments where there is only a single span, and the beams are laid side by side lengthwise` of thev roadway, there being for a roadway of 16 feet, 8 of the beams, vassuming that they are molded two feet in width. The number' of beams employed, however, willbe variedaccording to the width of the roadway and the dimensions of the beams.

I prefer to make the beams substantially T-shaped in cross section, there being a centrally arranged longitudinal web 6 depending from each beam and gradually decreasing in depth from the middle of the beam, each end merging into the flattened surfaces 3. At intervals transverse webs are formed, there being preferably'thre'e on each beam, a middle one 7, and one at each end indicated by reference' numerals S. These transverse websare substantially at right angles to the middle one and extend t0 the longitudinal edges of the beam and merge into the center web as indicated in Fig. 6.

The up )er surface or tread of each beam is reinforced and strengthened by a series of small rods or thereof at intervals and further strengthened by a series of short cross rods 1() extending tluough the tread of the beam from side to side, substantially at right angles to the rods 9. '.lhese rods 9 and l() lie in a plane parallel substantially with the top of the beam and serve to resist the crushing strain or load on the beam, and their number maybe varied according to the size of the bridge and the probable load to which it will be subjected. The longitudinal web of each beam is provided with a rod ll preferably of larger gageI than those described, and having its end l2 bent up around the cross rods l() at the extremities of the beam. The rod ll, as indicated in Fig'. 4 is curved or bowed downwardly following the configuration. of the web and having a truss ell`ectto resist the longitudinal strain or tension on the beam. I prefer to mold a curb 13 on the beams for use at the sides of the roadway and brace the same by rods 14 embedded therein at an angle to the tread of the beam, as indicated in Fig. 3, and also having bolts 16 to which the guard rails of the bridge may be secured.

The beams are molded in the manner described above and shipped from some con` wnes 9 running lengthwise provide plates l5 in each venient distributing point to the place where ing under surfaces at their ends to rest upon the workjs to be done, and when'the desired ythe bridge abutments or piers, the outer number of beams have been assembled for beams on each side having curbs formed inthe bridge I 'secure vthem together ,to make tegrally therewith, 'and cross rods' iitting 5 one homogeneous support or roadway by within holes in said beams andwhereby the 7a means' of a series of. cross rods 17 fitting said beamsmay be drawn snugly together to within holes 18 formed in the vtransverse form asmooth continuous roadway, substanwebs 7 and 8 and through the center web, tially as described. Y i the ends of said rods being threaded and 3. A bridge comprising a series of beams 10 having ck nuts that are tightened against; having flat upper surfaces and composed of 75 lplates 19 provided in sockets 2O in the outer concrete having reinforcing rods embedded beams of the series. Whenthe nuts on the therein and adapted to resist the .crushing cross rods are turned up the abutting ed es strain, said beams having webs extending of the beams will be drawn snugly tog'et er lengthwise thereof on the under side, and

andtheir upper surfaces will form a smooth rods 'embedded in said webs and curved or go continuous roadway that will bepractically bowed downwardly andhaving their ends indestructible. The reinforcing rods being anchored in the ends of said beams and said embedded in the beams will be thoroughlyy webrods having a truss effect to resist the protected and when the bridge is completed longitudinal stress or tension, and said beams 20 the holes20 will be filled with cement coverhaving cross webs at intervals extending s5- ances are at hand 'and weather conditions l 60 tia 1yv as described.

ing the ends of the rods 17 and protecting from side'to side and merging into said lonthemcfrom rust and deterioration by expo` gitudinal webs, and'said cross webs having sure to the weather. holes extending from side to sid`e of the In some instances when suitable applibeams, and rods fitting within said holes and having threaded ends and locknuts therefor, 9o permit, the beams may be molded at the and adapted todraw the beams snugly toy work and the brid e constructed inthe same gether and form a continuous roadway, submanner as it wouId be when the beams are stantially as described. v. molded and brought from adistance. I do 4. A bridge composed of a series of connot therefore, in' this application wish to be crete beams arranged lengthwise of the road- 95 conned to the idea o molding the beams way and each consisting of a ilat upper porand shipping them to the point where used, tion havingreinforcingrods extending length-- as l may at times find the other method-of wise and transversely therein, anda web dehandling the work preferable. pending from the underl side of each beam In place of the 'transverse rods securing the 'and extending lengthwise thereof along its 10o beams together andpreventing their lateral middle line, and a truss rod embeddedin separation I may rovide any other suitable said web and curved or bowed downwardly means yfor accomp ishing this same end, and and havin its ends bent around the trans-l in various ways the details of construction verse rein orcing rods at the ends of the 40 may be, modified without departing from the beam, and the rods embedded insaidupper 105 spirit of my invention. portion resisting the compression strain, and I- claim as my invention: p the truss rods embedded in said webs resisti 1. A bridge composed of a series of con-- ing the tension strain Aorstress, and said crete beams having -flat upper surfaces andy beams having-holes extending therethrough reinforcing rods extending lengthwise and from .side to side, and c oss rods passingllO cross wis'e thereofin said surfaces, and said through said holes and bindinglthe edges of beams fhaving webs -depending from their said beams snugly .to ether, w ereby'a conunder sides and extending lengthwise of the tinuous roadway' wil be` 'formed for the beams, said webs having curved lower edges bridge.

and decreasing -in depth from themiddle 5. A brid e span cdmposed'of a series lof 115,k f

toward each end, and rods embedded in said comparative y narrow beams of reinforced webs and bowed orcurved downwardly 'to concrete construction extending lengthwise Acoincide' with the curve of said webs, said 0f the bridge, there being a series of the rods having their ends anchored in the ends beams with contacting e ges from side to ofthe beams, and Vcross rods passing through side of the. bridge and each beam having a 12F holes provided in said beams and having web. depending rom its u'nder side and exthreaded ends and lock nuts therefor an tending lengthwise thereofalong the middle 4 adapted when tightened to draw the abutting line of the beam, reinforcing and truss rods ed es of said beams snugly together, substanembedded in said beam and web, and means l preventing lateral movement of the beams 2. A bridge composed of a series of beams andthe se aration of their contacting edges, of reinforced concrete construction, said, substantia ly as described. beafms being substantially T-shaped in cross 6. A bridgecom ose'd of concrete' beams section'and'adapted togbe'placed side bv side having ilongitudina yA arranged depending 1;'5 to form the roadway ofthe bridge an havwebs on their under-sides, and reinforcing and means for rods extending transversely of said beams near their upper surfaces and lengthwise thereof in'said webs to resist the crushing andtensile strains, said beams extending lengthwise of thebridge and contacting with one another from side to side of the bridge to .form 'a ,continuous roadway and means `preventing lateral movement of-said beams and' separation of their contacting edges.

7, A-bridge comprising a series of,b.earns composed of concrete having reinforcing rods embedded therein and adapted to resist the crushing strain, said beams having webs extending lengthwise thereof on the f under side, and rods embedded in said webs and curved or bowed downwardly and having their ends anchored .in the ends of said beams, and said web rods having a truss effeet to resist the longitudinal stress or tension, andsaid beams being adapted to be placed side by side lengthwise of the bridge, binding them together to form a continuous roadway, substantially as described. L

8. A bridge composed of concrete beams having reinforcing rods near their upper surfaces, said beams having webs extending lengthwise thereof, on their under side, and rods embedded in said webs with their ends anchored in the ends of the beams and their `irnddle portions curved or bowed down'- preventing Witnesses: 4

RICHARD PAUL, J. B. ERA.

one another to form a 

